EP 0087323 B1 19860903 - A PROCESS TO MANUFACTURE COMMERCIALLY ACCEPTABLE PHOSPHORIC ACID AND GYPSUM FROM ROCK PHOSPHATE
Title (en)
A PROCESS TO MANUFACTURE COMMERCIALLY ACCEPTABLE PHOSPHORIC ACID AND GYPSUM FROM ROCK PHOSPHATE
Publication
Application
Priority
GB 8205334 A 19820223
Abstract (en)
[origin: EP0087323A1] The present invention provides a process for the manufacture of gypsum and phosphate from rock phosphate, the process comprises solubilising the phosphate and fluoride content of rock phosphate by treating it with fluosilicic acid (H2SiF6) optionally together with phosphoric acid in a reactor (3), treating the solution so obtained, optionally after filtration in unit (4), with sulphuric acid in a crystalliser (7) to precipitate gypsum and regenerate fluosilicic acid, filtering the slurry to remove gypsum, dividing the remaining liquor into two portions, the major portion (10) being recycled to treat further rock phosphate, the minor portion being treated to remove the phosphoric acid content thereof in unit (12). The removed phosphoric acid constitutes the product of the process and fluosilicic acid remaining in the minor portion is recycled to treat further rock phosphate.
IPC 1-7
IPC 8 full level
C01B 25/22 (2006.01); C01F 11/46 (2006.01)
CPC (source: EP)
C01B 25/2208 (2013.01); C01F 11/46 (2013.01)
Citation (examination)
CHEMICAL ABSTRACTS, vol. 64, no. 9, 25th April 1966, columns 12234h-122356, Columbus, Ohio, USA S.Y. SHPUNT: "Production of phosphoric acid by decomposition of Mg-containing phosphate ores with H2SiF6"
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI LU NL SE
DOCDB simple family (publication)
EP 0087323 A1 19830831; EP 0087323 B1 19860903; AT E21882 T1 19860915; DE 3365775 D1 19861009
DOCDB simple family (application)
EP 83300957 A 19830223; AT 83300957 T 19830223; DE 3365775 T 19830223